xref: /dpdk/doc/guides/rel_notes/deprecation.rst (revision f5057be340e44f3edc0fe90fa875eb89a4c49b4f)
1..  SPDX-License-Identifier: BSD-3-Clause
2    Copyright 2018 The DPDK contributors
3
4ABI and API Deprecation
5=======================
6
7See the guidelines document for details of the :doc:`ABI policy
8<../contributing/abi_policy>`. API and ABI deprecation notices are to be posted
9here.
10
11Deprecation Notices
12-------------------
13
14* meson: The minimum supported version of meson for configuring and building
15  DPDK will be increased to v0.47.1 (from 0.41) from DPDK 19.05 onwards. For
16  those users with a version earlier than 0.47.1, an updated copy of meson
17  can be got using the ``pip3`` tool (or ``python3 -m pip``) for downloading
18  python packages.
19
20* kvargs: The function ``rte_kvargs_process`` will get a new parameter
21  for returning key match count. It will ease handling of no-match case.
22
23* eal: To be more inclusive in choice of naming, the DPDK project
24  will replace uses of master/slave in the API's and command line arguments.
25
26  References to master/slave in relation to lcore will be renamed
27  to initial/worker.  The function ``rte_get_master_lcore()``
28  will be renamed to ``rte_get_initial_lcore()``.
29  For the 20.11 release, both names will be present and the
30  old function will be marked with the deprecated tag.
31  The old function will be removed in a future version.
32
33  The iterator for worker lcores will also change:
34  ``RTE_LCORE_FOREACH_SLAVE`` will be replaced with
35  ``RTE_LCORE_FOREACH_WORKER``.
36
37  The ``master-lcore`` argument to testpmd will be replaced
38  with ``initial-lcore``. The old ``master-lcore`` argument
39  will produce a runtime notification in 20.11 release, and
40  be removed completely in a future release.
41
42* eal: The terms blacklist and whitelist to describe devices used
43  by DPDK will be replaced in the 20.11 relase.
44  This will apply to command line arguments as well as macros.
45
46  The macro ``RTE_DEV_BLACKLISTED`` will be replaced with ``RTE_DEV_EXCLUDED``
47  and ``RTE_DEV_WHITELISTED`` will be replaced with ``RTE_DEV_INCLUDED``
48  ``RTE_BUS_SCAN_BLACKLIST`` and ``RTE_BUS_SCAN_WHITELIST`` will be
49  replaced with ``RTE_BUS_SCAN_EXCLUDED`` and ``RTE_BUS_SCAN_INCLUDED``
50  respectively. Likewise ``RTE_DEVTYPE_BLACKLISTED_PCI`` and
51  ``RTE_DEVTYPE_WHITELISTED_PCI`` will be replaced with
52  ``RTE_DEVTYPE_EXCLUDED`` and ``RTE_DEVTYPE_INCLUDED``.
53
54  The old macros will be marked as deprecated in 20.11 and any
55  usage will cause a compile warning. They will be removed in
56  a future release.
57
58  The command line arguments to ``rte_eal_init`` will change from
59  ``-b, --pci-blacklist`` to ``-x, --exclude`` and
60  ``-w, --pci-whitelist`` to ``-i, --include``.
61  The old command line arguments will continue to be accepted in 20.11
62  but will cause a runtime warning message. The old arguments will
63  be removed in a future release.
64
65* eal: The function ``rte_eal_remote_launch`` will return new error codes
66  after read or write error on the pipe, instead of calling ``rte_panic``.
67
68* rte_atomicNN_xxx: These APIs do not take memory order parameter. This does
69  not allow for writing optimized code for all the CPU architectures supported
70  in DPDK. DPDK will adopt C11 atomic operations semantics and provide wrappers
71  using C11 atomic built-ins. These wrappers must be used for patches that
72  need to be merged in 20.08 onwards. This change will not introduce any
73  performance degradation.
74
75* rte_smp_*mb: These APIs provide full barrier functionality. However, many
76  use cases do not require full barriers. To support such use cases, DPDK will
77  adopt C11 barrier semantics and provide wrappers using C11 atomic built-ins.
78  These wrappers must be used for patches that need to be merged in 20.08
79  onwards. This change will not introduce any performance degradation.
80
81* igb_uio: In the view of reducing the kernel dependency from the main tree,
82  as a first step, the Technical Board decided to move ``igb_uio``
83  kernel module to the dpdk-kmods repository in the /linux/igb_uio/ directory
84  in 20.11.
85  Minutes of Technical Board Meeting of `2019-11-06
86  <https://mails.dpdk.org/archives/dev/2019-November/151763.html>`_.
87
88* lib: will fix extending some enum/define breaking the ABI. There are multiple
89  samples in DPDK that enum/define terminated with a ``.*MAX.*`` value which is
90  used by iterators, and arrays holding these values are sized with this
91  ``.*MAX.*`` value. So extending this enum/define increases the ``.*MAX.*``
92  value which increases the size of the array and depending on how/where the
93  array is used this may break the ABI.
94  ``RTE_ETH_FLOW_MAX`` is one sample of the mentioned case, adding a new flow
95  type will break the ABI because of ``flex_mask[RTE_ETH_FLOW_MAX]`` array
96  usage in following public struct hierarchy:
97  ``rte_eth_fdir_flex_conf -> rte_fdir_conf -> rte_eth_conf (in the middle)``.
98  Need to identify this kind of usages and fix in 20.11, otherwise this blocks
99  us extending existing enum/define.
100  One solution can be using a fixed size array instead of ``.*MAX.*`` value.
101
102* mbuf: Some fields will be converted to dynamic API in DPDK 20.11
103  in order to reserve more space for the dynamic fields, as explained in
104  `this presentation <https://www.youtube.com/watch?v=Ttl6MlhmzWY>`_.
105  The following static fields will be moved as dynamic:
106
107  - ``timestamp``
108  - ``userdata`` / ``udata64``
109  - ``seqn``
110
111  As a consequence, the layout of the ``struct rte_mbuf`` will be re-arranged,
112  avoiding impact on vectorized implementation of the driver datapaths,
113  while evaluating performance gains of a better use of the first cache line.
114
115
116* ethdev: the legacy filter API, including
117  ``rte_eth_dev_filter_supported()``, ``rte_eth_dev_filter_ctrl()`` as well
118  as filter types MACVLAN, ETHERTYPE, FLEXIBLE, SYN, NTUPLE, TUNNEL, FDIR,
119  HASH and L2_TUNNEL, is superseded by the generic flow API (rte_flow) in
120  PMDs that implement the latter.
121  The legacy API will be removed in DPDK 20.11.
122
123* ethdev: The flow director API, including ``rte_eth_conf.fdir_conf`` field,
124  and the related structures (``rte_fdir_*`` and ``rte_eth_fdir_*``),
125  will be removed in DPDK 20.11.
126
127* ethdev: The legacy L2 tunnel filtering API is deprecated as the rest of
128  the legacy filtering API.
129  The functions ``rte_eth_dev_l2_tunnel_eth_type_conf`` and
130  ``rte_eth_dev_l2_tunnel_offload_set`` which were not marked as deprecated,
131  will be removed in DPDK 20.11.
132
133* ethdev: Update API functions returning ``void`` to return ``int`` with
134  negative errno values to indicate various error conditions (e.g.
135  invalid port ID, unsupported operation, failed operation):
136
137  - ``rte_eth_dev_stop``
138  - ``rte_eth_dev_close``
139
140* ethdev: New offload flags ``DEV_RX_OFFLOAD_FLOW_MARK`` will be added in 19.11.
141  This will allow application to enable or disable PMDs from updating
142  ``rte_mbuf::hash::fdir``.
143  This scheme will allow PMDs to avoid writes to ``rte_mbuf`` fields on Rx and
144  thereby improve Rx performance if application wishes do so.
145  In 19.11 PMDs will still update the field even when the offload is not
146  enabled.
147
148* ethdev: Add new fields to ``rte_eth_rxconf`` to configure the receiving
149  queues to split ingress packets into multiple segments according to the
150  specified lengths into the buffers allocated from the specified
151  memory pools. The backward compatibility to existing API is preserved.
152
153* ethdev: ``rx_descriptor_done`` dev_ops and ``rte_eth_rx_descriptor_done``
154  will be removed in 21.11.
155  Existing ``rte_eth_rx_descriptor_status`` and ``rte_eth_tx_descriptor_status``
156  APIs can be used as replacement.
157
158* ethdev: The port mirroring API can be replaced with a more fine grain flow API.
159  The structs ``rte_eth_mirror_conf``, ``rte_eth_vlan_mirror`` and the functions
160  ``rte_eth_mirror_rule_set``, ``rte_eth_mirror_rule_reset`` will be marked
161  as deprecated in DPDK 20.11, along with the associated macros ``ETH_MIRROR_*``.
162  This API will be fully removed in DPDK 21.11.
163
164* ethdev: The ``struct rte_flow_item_eth`` and ``struct rte_flow_item_vlan``
165  structs will be modified, to include an additional value, indicating existence
166  or absence of a VLAN header following the current header, as proposed in RFC
167  https://mails.dpdk.org/archives/dev/2020-August/177536.html.
168
169* ethdev: The ``struct rte_flow_item_ipv6`` struct will be modified to include
170  additional values, indicating existence or absence of IPv6 extension headers
171  following the IPv6 header, as proposed in RFC
172  https://mails.dpdk.org/archives/dev/2020-August/177257.html.
173
174* security: The API ``rte_security_session_create`` takes only single mempool
175  for session and session private data. So the application need to create
176  mempool for twice the number of sessions needed and will also lead to
177  wastage of memory as session private data need more memory compared to session.
178  Hence the API will be modified to take two mempool pointers - one for session
179  and one for private data.
180
181* cryptodev: ``RTE_CRYPTO_AEAD_LIST_END`` from ``enum rte_crypto_aead_algorithm``,
182  ``RTE_CRYPTO_CIPHER_LIST_END`` from ``enum rte_crypto_cipher_algorithm`` and
183  ``RTE_CRYPTO_AUTH_LIST_END`` from ``enum rte_crypto_auth_algorithm``
184  will be removed.
185
186* cryptodev: support for using IV with all sizes is added, J0 still can
187  be used but only when IV length in following structs ``rte_crypto_auth_xform``,
188  ``rte_crypto_aead_xform`` is set to zero. When IV length is greater or equal
189  to one it means it represents IV, when is set to zero it means J0 is used
190  directly, in this case 16 bytes of J0 need to be passed.
191
192* scheduler: The functions ``rte_cryptodev_scheduler_slave_attach``,
193  ``rte_cryptodev_scheduler_slave_detach`` and
194  ``rte_cryptodev_scheduler_slaves_get`` will be replaced in 20.11 by
195  ``rte_cryptodev_scheduler_worker_attach``,
196  ``rte_cryptodev_scheduler_worker_detach`` and
197  ``rte_cryptodev_scheduler_workers_get`` accordingly.
198
199* eventdev: Following structures will be modified to support DLB PMD
200  and future extensions:
201
202  - ``rte_event_dev_info``
203  - ``rte_event_dev_config``
204  - ``rte_event_port_conf``
205
206  Patches containing justification, documentation, and proposed modifications
207  can be found at:
208
209  - https://patches.dpdk.org/patch/71457/
210  - https://patches.dpdk.org/patch/71456/
211
212* acl: ``RTE_ACL_CLASSIFY_NUM`` enum value will be removed.
213  This enum value is not used inside DPDK, while it prevents to add new
214  classify algorithms without causing an ABI breakage.
215
216* sched: To allow more traffic classes, flexible mapping of pipe queues to
217  traffic classes, and subport level configuration of pipes and queues
218  changes will be made to macros, data structures and API functions defined
219  in "rte_sched.h". These changes are aligned to improvements suggested in the
220  RFC https://mails.dpdk.org/archives/dev/2018-November/120035.html.
221
222* sched: To allow dynamic configuration of the subport bandwidth profile,
223  changes will be made to data structures ``rte_sched_subport_params``,
224  ``rte_sched_port_params`` and new data structure, API functions will be
225  defined in ``rte_sched.h``. These changes are aligned as suggested in the
226  RFC https://mails.dpdk.org/archives/dev/2020-July/175161.html
227
228* metrics: The function ``rte_metrics_init`` will have a non-void return
229  in order to notify errors instead of calling ``rte_exit``.
230
231* power: ``rte_power_set_env`` function will no longer return 0 on attempt
232  to set new power environment if power environment was already initialized.
233  In this case the function will return -1 unless the environment is unset first
234  (using ``rte_power_unset_env``). Other function usage scenarios will not change.
235
236* dpdk-setup.sh: This old script relies on deprecated stuff, and especially
237  ``make``. Given environments are too much variables for such a simple script,
238  it will be removed in DPDK 20.11.
239  Some useful parts may be converted into specific scripts.
240